<template>
  <div>
    <h1>第四题</h1>

    <button @click="copy">复制</button>
  </div>
</template>

<script>
export default {
  data() {
    return {
      arr: [1, 2, 3, 4, 5],
      brr: [],
    };
  },
  methods: {
    copy(target) {
      this.brr = this.arr.concat();
      this.arr.push(100);
      console.log(this.brr);
    },
  },
};
</script>

<style>
</style>
